Note: Descriptions are shown in the official language in which they were submitted.
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Spacer suited for being embedded in concrete
. The present invention relates to a spacer suited for being
embedded in concrete, for use with wire reinforcements
~' placed in the walls of concrete pipes cast in molds.
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Known spacers of this type are designed as slotted plastic
disks which are fitted by their slots on predetermined
points of the wire reinforcement. Xowever, during the opera-
tion of mounting the wire reinforcement on a mold core, with
the disks fitted thereon, or of placing an outer mold around
the wire reinforcement, with the spacers fitted thereon, the
spacers tend to get distorted so that the wire reinforce-
ments are no longer held centrically in the mold, whereby
the ~uality of the finished concrete pipe may be impaired.
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Now, it is the object of the present invention to remedy the
described drawback and to propose a spacer of the type described
above which is capable of holding the reinforcement in an exactly
concentric position in the mold and which will not be deformed,
not even i~ relative movements should occur between the
reinforcement and the mold.
In accordance with the invention there is provided a spacer
suited for being embedded in concrete, for use with wire
reinforcements placed in the walls of con~rete pipes cast in
molds, comprising a main body made of a polymer concrete. The
main body is provided at a first side with a spacer element
projecting from the main body in a radial direction of a concrete
pipe to be prepared, and terminating by an inclined surface
extending in an axial direction of the concrete pipe to be
prepared, for assisting sliding movement when mounting a mold
over a wire reinforcement having spacers mounted thereon. The
main body is provided on a second side with a groove for
receiving a section of a first wire of the wire rsinforcement,
the second side being radially opposite to the first side. The
main body is further provided with at least two mounting elements
designed as resilient elements having one end embedded in the
main body, the two mounting elements being disposed at opposite
sides o~ the groove. The resilient mounting elements project
from the second side of the main body in radial direction, each
resilient mounting element being designed to be clipped on a
second wire of the wire reinforcement, the second wire extending
substantially perpendicular to the first wire sectionally
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disposed within the groove.
Further details of the invention will become apparent from the
following description of preferred embodiments of the invention
in conjunction with the attached drawing, in which:
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Fig. 1 is a diagrammatic view of a mold intended for casting
concrete pipes, with two wire reinforcements arranged in the
concrete wall;
Fig. 2 shows a cross-sectional view along line 2-2 in Fig. 1;
Fig. 3 shows a cross-sectional view of the detail indicated by
the circle A in Fig. l;
Fig. 4 shows a perspective view of a first spacer; and
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fig. 5 shows a perspective view of a second spacer.
The mold illustrated in fig. 1, which is intended for cast-
ing concrete pipes of relatively large dimensions, for
example in lengths of 3 m and with diameters of 1.20 m, com-
prises an inner core 1 projecting upwardly from a circular
base plate over a length corresponding to the length of the
concrete pipe to be cast. The inner core 1 is enclosed by an
inner wire rein~orcement 3 and an outer wire reinforcement 4
spaced a certain distance from the said wire reinforcement
3. The wire reinforcements 3, 4 comprise vertically extend-
ing metal bars 5 which also correspond substantially to the
length of the finished concrete pipe and which are supported
by the base plate 2. The metal bars 5 are connected, for
example by welding, to substantially circular peripheral
sections 6 which likewise consist of metal. Usually, the
sections 6 form a spiral along 1:he vertical bars 5. Conse-
quently, the inner and outer wir.e reinforcements 3, 4 form
self-supporting cages which may also be connected to each
other.
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Spacers 7, 8 - which will be described in more detail
further below - mounted on the wire reinforcements 3, 4
serve to hold the latter in a concentric position relative
to the center axis of the inner core 1, and at an exactly
defined spacing therefrom, the inner spacer 7, which is
connected to the inner wire reinforcement, being in contact
with the outer circumferential surface of the inner core 1,
while the spacers 8, which are connected with the outer wire
: reinforcement, are in contact with an outer mold 9 which is
fitted upon the inner core 1, in the direction indicated by
arrow B, after the wire reinforcements 3, 4 with the spacers
7, 8 mounted thereon have been arranyed about the inner core
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As the inner wire reinforcement 3 is mounted on the inner
core 1, the spacers 7 slide along the latter's outer cir-
cumferential surface and ensure in this manner that the
inner reinforcement is exactly centered. When the inner wall
of the outer mold 9 ls mounted on the inner core 1, it
slides along the spacers 8 whereby the wire reinforcement 4
is centered.
Once the wire reinforcements 3, 4 have been mounted on the ~~
inner core and the outer mold 9 has been fitted in place,
concrete is filled into the space between the inner core 1
and the mold 9, in the area of the wire reinforcements 3, 4.
The inner core 1, together with the base plate 2 supporting
the outer mold 9, are preferably placed on a vibrating table
so that the concrete, which has been filled into the mold,
can be compacted as desired.
Figs. 3 to 5 illustrate in detail the structure and opera-
tion of the spacers 7, 8.
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~` The spacer 7 mounted on the inner wire reinforcement 3
comprises a basic body 11 made Erom a material whose thermal
coefficient of expansion is substantially equal to that of
the concrete used for the production of the pipe. Preferab-
ly, a concrete polymer, i.e. a mixture of a plastic material
and sand, cement or the like, may be used for this purpose.
One side of the basic body 11 (the right side in figs. 3 and
; 4) is provided with radially projecting mounting elements
`~ which serve as connection between the basic body and the
inner wire reinforcement 3. These mounting elements comprise
two lower wire elements 12 of curved shape which project
from the basic body 11 and which are firmly inserted into
~i the latter. Each of these wire elements 12 is intended for
receiving a peripheral portion 6 of the wire reinforcament 3
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` from below, in form-locking or frictional engagement, and
can be clicked easily upon the matching section 6. Two
further wire elements 13 arranged one beside the other above
the wire elements 12 engage the metal bar in frictional or
form-locking manner so that they, too, enable the mounting
element to be clicked upon the bar 5.
The side of the basic body 11 radially opposite the wire
elements 12, 13 is equipped with a spacer element 14 in the
form of a rib which projects in a direction radially
opposite to the wire elements 12, 13 and which terminates by
an inclined surface 15 extending substantially in axial
direction and serving to facilitate the sliding movement
along the inner core 1.
As appears from figs. 1 and 2, several spacers 17 are
:~ mounted in vertically and peripherally spaced arrangement on
the inner wire reinforcement before the latter is positioned
on the inner core 1. During the sliding positioning move-
ment, the inclined surfaces 5 slide along the outer surface
of the inner core 1 50 that the highest point of the rib 14
projecting the farthest to the inside comes to rest against
the inner core 1 whereby it ensures the desired centering of
the wire reinforcement 3. As th,e wire elements 12 embrace
the sections 6 of the reinforcement from below, the spacers
7 are prevented from being dislodged in upward direction by
. the sliding movement between the reinforcement 3 and the
inner core 1.
Advantageously, an additional section 6 of the reinforcement
is left between the two wire elements 12, 13 for supporting
the wall of the basic body from which the wire elements 12,
13 project (see fig. 3).
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The spacer 8 provided on the outer wire reinforcement 4
comprises likewise a basic body 16 consisting, for example,
of a concrete polymer. Two wire elements 17 projecting from
the upper end of the said body 16 correspond substantially
to the wire elements 11 provided on the spacer 7, except
that they engage the matching perlpheral section 6 of the
wire reinforcement from above, rather than from below. The
wall ~rom which the wire elements 17 project is provided
with a groove 18 receiving part of the vertically extending
metal bar thereby providing a vertical support for the
spacer 8. The basic body 16 is again provided, on the side
opposite the wire element 17, with a rib 19 with an inclined
surface 21. When the outer wire reinforcement 4, together
with the spacers 8, is placed upon the base plate 2 of the
inner mold core 1 and the outer mold 9 is moved in place
over the assembly, the outer mold comes to slide initially
along the inclined surfaces 21 of the spacers 8, thereb~
centering the rein~orcement 4, ~hile in the end position the
crown points of the rib 19 projecting the farthest in the
radial direction come to rest against the inner face of the
outer mold 9.
As illustrated in the drawing, all of the peripheral sec-
tions 6 of the wire reinforcements 3, 4 are arranged on the
sides of the vertical metal bars 6 facing the inner core 1.
~t is ensured in this manner that the wall from which the
wire elements 12, 13 of the spacer 7 project rests against
peripheral sections 6 of the wire reinforcement 3, while the
groove 18 of each spacer 8 engages a vertical bar 5.
The design of the spacers 7, 8 and their connection with the.
wire reinforcements 3, 4 are sturdy enough to ensure that
they cannot get dislodged or distorted by any relative
movements between the reinforcements and the parts 1 and 9
of the mold so that the reinforcements 3, 4 will in any case
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occupy an exactly centered position in the annular space ofthe mold to be filled with concrete. The distance between
the wire reinforcements 3, 4 and the inner core 1 of the
outer mold 9 is determined in any case by the crown heights
of the projecting ribs 14, 19.
In the case of the embodiments of the mounting elements,
i.e. the wire elements 12, 13 and 17, described 50 far all
these elements are designed as parts separate from the basic
body 11, 16. ~owever, according to certain modi~ied
embodiments of these spacers, the mounting elements which
serve for connecting the spacers with the wire reinforce-
ments 3, 4 may also be formed integrally with the basic body
11, 16, which means that they may also consist of a concrete
polymer, for example, and may be formed together with the
spacers 7, 8 by the same molding or injection-molding
process. For example, the basic bodies 11, 16 may be
provided with projections which may be formed integrally
from a concrete polymer and which may hav0 a height similar
to that of the wire elements 12, 13, 17, for engaging the
wire reinforcements 3, 4 in the same manner as the wire
elements 12, 13 and 17.
As appears particularly clearly from fig. 3, the crown of
the curved rib 14, which performs the function of a spacer
element, has the shape of a segment of a circle whose center
coincides substantially with the center line of the
peripheral section 6 of the wire reinforcement 3 which is
sngaged by the wire element 12. If, therefore, the spacer 7
should come to tilt about the peripheral reinforceme~t
section 6, during application of the inner reinforcement 3
on the inner core 1, for example due to the fact that the
wire elements 13 get dislodged from the metal bar 5, such
tilting would not change in any way the prescribed spacing
between the wire reinforcement 3 and the outer wall of the
inner core 1 as the crown of the rib 14 would insofar act as
a circular roller.
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Besides, a similar design in the form a circular disk may be
provided also for the rib 19 in the area of its surface of
contact with the inner wall of the outer mold 9. The con- -
crete pipe described with reference to figs. 1 and 2 is a
pipe with continuous wall. However, the described spacers
can be used similarly for conventional concrete pipes of the
type provided with a slot extending parallel to the pipe
axis. Such "slotted" pipes are used, for ex.ample, as water
drain pipes along highways in which case the water running
off the road surface enters the interior of the pipe through
the slot.
As will be seen best in figs. 3 to 5, the mounting elements
(wire elements 12) are arranged in the lower area of the
spacer 7, while the mounting elements (wire elements 17) are
arranged in the upper aree of the spacer 8.
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